Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Non-nullable event 'QrCodeRefresh' must contain a non-null value when exiting constructor. Consider declaring the event as nullable.

Non-nullable event 'QrCodeUrlRefresh' must contain a non-null value when exiting constructor. Consider declaring the event as nullable.

Non-nullable event 'QrCodeStatus_Changed' must contain a non-null value when exiting constructor. Consider declaring the event as nullable.

Converting null literal or possible null value to non-nullable type.